參數(shù)資料
型號(hào): LMC7225
文件頁數(shù): 9/14頁
文件大?。?/td> 277K
代理商: LMC7225
Application Information
(Continued)
Note that very heavy loading of the comparator output, such
as LED drive or bipolar logic gates, will change the output
voltage and shift the voltage thresholds.
TL/H/12337–9
R
F
n
R
1
and
R
F
n
R
2
FIGURE 4. Positive Feedback for Hysteresis
Without Positive Feedback
(No Hysteresis)
TL/H/12337–10
FIGURE 5
With Positive Feedback
(Hysteresis or Memory)
TL/H/12337–11
FIGURE 6
6.0 Input Protection
If input signals are like to exceed the common mode range
of the LMC7211, or it is likely that signals may be present
when power is off, damage to the LMC7211 may occur.
Large value (100 k
X
to M
X
) input resistors may reduce the
likelihood of damage by limiting the input currents. Since the
LMC7211 has very low input leakage currents, the effect on
accuracy will be small. Additional protection may require the
use of diodes, as shown in Figure 7. Note that diode leak-
age current may affect accuracy during normal operation.
The R-C time constant of R
IN
and the diode capacitance
may also slow response time.
TL/H/12337–12
FIGURE 7
7.0 Layout Considerations
The LMC7211 is not an especially fast comparator, so high
speed design practices are not required. The LMC7211 is
capable of operating with very high impedance inputs, so
precautions should be taken to reduce noise pickup with
high impedance (
E
100 k
X
and greater) designs and in
electrically noisy environments.
Keeping high value resistors close to the LMC7211 and min-
imizing the size of the input nodes is a good practice. With
multilayer designs, try to avoid long loops which could act
as inductors (coils). Sensors which are not close to the
comparator may need twisted pair or shielded connections
to reduce noise.
8.0 Open Drain Output, Dual
Versions
The LMC7221 is a comparator similar to the LMC7211, but
with an open drain output which allows the output voltage to
be different (higher or lower) than the supply voltage. The
open drain output is like the open collector output of a logic
gate. This makes the LMC7221 very useful for mixed volt-
age systems. Many systems will have different voltages for
the analog and microprocessor sections. Please see the
LMC7221 datasheet for details.
The performance of the LMC7211 is available in dual devic-
es. Please see the LMC6762 datasheet for details on a dual
push-pull output device. For a dual device with open drain
outputs, please see the LMC6772 datasheet.
9
相關(guān)PDF資料
PDF描述
LMC7532
LMC7660MJ DC-to-DC Voltage Converter
LMF100AJ Analog Filter
LMF100CCWM Analog Filter
LMF100CIWMX Analog Filter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LMC7225IM 功能描述:IC COMPAR MCRPWR CMOS RR 8-SOIC RoHS:否 類別:集成電路 (IC) >> 線性 - 比較器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:通用 元件數(shù):1 輸出類型:CMOS,推挽式,滿擺幅,TTL 電壓 - 電源,單路/雙路(±):2.5 V ~ 5.5 V,±1.25 V ~ 2.75 V 電壓 - 輸入偏移(最小值):5mV @ 5.5V 電流 - 輸入偏壓(最小值):1pA @ 5.5V 電流 - 輸出(標(biāo)準(zhǔn)):- 電流 - 靜態(tài)(最大值):24µA CMRR, PSRR(標(biāo)準(zhǔn)):80dB CMRR,80dB PSRR 傳輸延遲(最大):450ns 磁滯:±3mV 工作溫度:-40°C ~ 85°C 封裝/外殼:6-WFBGA,CSPBGA 安裝類型:表面貼裝 包裝:管件 其它名稱:Q3554586
LMC7225IM5 功能描述:校驗(yàn)器 IC RoHS:否 制造商:STMicroelectronics 產(chǎn)品: 比較器類型: 通道數(shù)量: 輸出類型:Push-Pull 電源電壓-最大:5.5 V 電源電壓-最小:1.1 V 補(bǔ)償電壓(最大值):6 mV 電源電流(最大值):1350 nA 響應(yīng)時(shí)間: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SC-70-5 封裝:Reel
LMC7225IM5/NOPB 功能描述:校驗(yàn)器 IC 1Ua Tiny Comp-Open Drain RoHS:否 制造商:STMicroelectronics 產(chǎn)品: 比較器類型: 通道數(shù)量: 輸出類型:Push-Pull 電源電壓-最大:5.5 V 電源電壓-最小:1.1 V 補(bǔ)償電壓(最大值):6 mV 電源電流(最大值):1350 nA 響應(yīng)時(shí)間: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SC-70-5 封裝:Reel
LMC7225IM5/NOPB 制造商:Texas Instruments 功能描述:Voltage Comparator IC
LMC7225IM5X 功能描述:校驗(yàn)器 IC RoHS:否 制造商:STMicroelectronics 產(chǎn)品: 比較器類型: 通道數(shù)量: 輸出類型:Push-Pull 電源電壓-最大:5.5 V 電源電壓-最小:1.1 V 補(bǔ)償電壓(最大值):6 mV 電源電流(最大值):1350 nA 響應(yīng)時(shí)間: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SC-70-5 封裝:Reel